1. Field of the Invention
This invention relates to a structure for installing a flexible printed circuit board for allowing a flexible printed circuit board to be installed between members moving relatively to each other.
2. Description of the Related Art
Flexible printed circuit boards (hereinafter abbreviated as FPC boards) are indispensable electric parts in performing an electrical installation on compact equipment, and the field of its applications tends to expand with progress in semiconductor technology.
When an FPC board is installed between members moving relatively to each other, how to deal with a slackened portion occurring in the FPC board when the distance between the members becomes small is an important problem.
Conventionally, as methods of installing an FPC board between members moving relatively to each other, various methods are known (e.g. U.S. Pat. No. 4,596,454). For example, there is a method in which a belt-shaped FPC board is fixed to two members moving relatively to each other, a U-turn portion which moves in correspondence with variations in the relative distance between the relatively moving members is formed between fixing points, and the slackened portion is absorbed by the U-turn portion when the relative distance between the members becomes small. In the structure for installing the FPC board in accordance with this method, there is an advantage in that a large space for the slackened portion of the FPC board between the members is not required since the slackened portion is absorbed as the U-turn portion moves in parallel with the direction of the relative movement of the members.
However, in an apparatus in which a multiplicity of FPC boards having the above-described construction needs to be installed, a multiplicity of spaces for the movement of the U-turn portions of the FPC boards are required, so that it is necessary to form substantial spaces in the vicinity of the relatively moving members and between the relatively moving members. Hence, there has been the drawback that the apparatus becomes large in size as a result.